Symfony 5: The Fast Track is the best book to learn
modern Symfony development, from zero to production. +300 pages in full color showing how to
combine Symfony with Docker, APIs, queues & async tasks, Webpack, Single-Page Applications, etc.
phpspec is a tool which can help you write clean and working PHP code
using behaviour driven development or BDD. It's also a PHP toolset to
drive emergent design by specification.